1. Field of Invention
This invention relates to the field of illuminated display devices, and in particular to miniature astronomical display devices which employ ultraviolet illumination with phosphorescent and fluorescent display objects.
2. Description of the Prior Art
The prior art contains various three-dimensional viewing devices, such as the Three-Dimensional Space Viewing Device of U.S. Pat. No. 4,167,074. This patent teaches the illusion of movement in space by providing an ultraviolet illuminated background scene which moves behind foreground scenes which are illuminated with ordinary light.
U.S. Pat. No. 4,016,450 discloses a phosphorescent exit sign which is periodically charged by an ultraviolet light; the sign glows after the intermittent flashing of the ultraviolet light.
U.S. Pat. No. 3,089,259 discloses a box-like display cabinet with ultraviolet illumination and an electrical motor-driven representation of the sun and planets.
U.S. Pat. No. 3,068,010 discloses a game in which answers to questions or other information are prepared in fluorescent paint and thus only visible upon activation of an ultraviolet light source. The game is played by first observing the question under ordinary illumination and then after guessing the answer activating the ultraviolet light source to display the answer.
U.S. Pat. No. 2,015,170 discloses a billboard with two displays and two sources of light, one being ordinary and the other ultraviolet. Thus the scene visible under ordinary light may be changed by extinguishing the ordinary light and activating the ultraviolet light which makes the previously invisible second display become visible.
However, a problem unsolved in the prior art is to provide two astronomical displays both filling the same cabinet and both of which possess the pleasing effect of ultraviolet illumination.